Embodiments of the present invention relate to a contact of a semiconductor device.
Typically, in order to reduce contact resistance of a contact in a semiconductor device, a metal silicide layer is formed between a contact region of a semiconductor substrate and a contact or plug. That is, silicification in which silicon (Si) contained in the contact region of the semiconductor substrate is reacted with a metal material contained in a metal layer, which forms a metal silicide film between the contact region and the contact, such that contact resistance or interfacial resistance between the contact and the contact region can be reduced.
Generally, it is known to those skilled in the art that a cleaning process is performed to remove impurities from the surface of the contact region, a metal layer is formed over the cleaned contact region, and a silicification process is then performed on the resultant metal layer in such a manner that a metal silicide film can be effectively formed over the contact region.